Howdy. On devices with the appropriate ACPI tables (and hw), battery information is reported during boot:
https://github.com/openbsd/src/blob/master/sys/dev/acpi/acpibat.c#L84 which shows up like this on my toughbook: Aug 11 21:22:48 ndnd /bsd: acpibat0 at acpi0: BAT1 model "CF-VZSU71" serial 00775 type LION oem "Panasonic" When acpibat_getbix (https://github.com/openbsd/src/blob/master/sys/dev/acpi/acpibat.c#L320) is called (initially in acpibat_attach and periodically in acpibat_notify), the main acpibat_softc struct is re-populated with this information but it's not available in either a log message, APM event, or in a sysctl node. I realize that not all hardware propagates this info accurately (https://github.com/openbsd/src/blob/master/sys/dev/acpi/acpibat.c#L466) and that not every machine has a user removable battery but in the event that it does, what's the best way to report/query this information? I don't mind submitting a patch, I just want to get folks guidance/preference on the approach. +--+ Carlos